An imaging lens includes a first lens having positive curvature radii on both an object side and an image side, a second lens having a concave shape on both sides, and a third lens having positive curvature radii on both the object side and the image side. The first to third lenses are arranged in this order from the object side toward the image side. When a whole lens system has a focal length f, the first lens has a focal length f1, the second lens has a focal length f2, and the third lens has a focal length f3, the following conditional expressions are satisfied: f1